The present invention relates to a locking device for fixing a child seat to a vehicle seat by a webbing of a seat belt device and, more particularly, to a locking device employing a clamping roller for clamping the webbing of the seat belt device.
For mounting a child seat on a vehicle seat, the child seat is normally fixed by a webbing of a seat belt device for an adult occupant. Disclosed in GB 2288202A is a locking device employing a clamping roller for clamping the webbing. The clamping roller is provided with serrations or projections around the outer periphery thereof which extend parallel to the axis of the roller. A shoulder webbing of the seat belt device can be clamped between the roller and stepped surfaces confronting the roller.
For clamping the shoulder webbing of the seat belt device by the clamping roller, the axial direction of the clamping roller should be substantially perpendicular to the longitudinal direction of the webbing. The shoulder webbing is arranged to extend upwardly diagonally from the right side to the left side or from the left side to the right side along the seat back of the seat. That is, one end of the shoulder belt is connected to a tongue engaging a buckle which is arranged at a middle of a vehicle body, and the other end of the shoulder belt is hooked at an upper portion of a pillar of the vehicle body. Therefore, in case of a left-side seat of the vehicle, the shoulder webbing extends upwardly diagonally from the right side to the left side. On the other hand, in case of a right-side of the vehicle, the shoulder webbing extends upwardly diagonally from the left side to the right side.
In GB 2288202A, two clamping units are used which are a left-side clamping unit for locking the shoulder webbing of the left-side seat, and a right-side clamping unit for locking the shoulder webbing of the right-side seat.
It is an object of the present invention to provide a locking device for a child seat, which can clamp a shoulder belt on either the left-side seat or the right-side seat by means of one clamping roller.